The 28-year-long quest to find the killer of two young French boys who had their skulls smashed in with rocks took a new twist this week when a 65-year-old man was charged with the crime. But have French police finally found their man?

A French court on Tuesday charged a man with the grisly murder 28 years ago of two young boys, the latest twist in a legal saga that has seen a serial killer and a teenager also accused.

Henri Leclaire, 65, a short and stocky former warehouse worker, was charged with killing eight-year-olds Cyril Beining and Alexandre Beckrich, who were found dead in September 1986, their skulls smashed with rocks.

Leclaire, who denies the charges, was released on bail and his lawyer said he would "demonstrate for sure that he is not involved in this case".

"There's nothing substantial against Henri Leclaire. The only problem with this case is the initial confessions," the lawyer, Thomas Hellenbrand, told reporters after a two-hour hearing in the eastern city of Metz.

Leclaire in fact initially confessed to the twin murders before retracting.

Detectives eliminated Leclaire from their enquiries, firmly convinced that Patrick Dils, a reclusive adolescent of 16 at the time, had committed the murders.

Dils was handed a life sentence before being acquitted and freed in 2002 after 15 years behind bars and a gruelling legal saga involving three retrials - the first time someone had ever been tried three times for the same crime in France.

He had also initially confessed to killing the two young boys and later retracted.

Dils was acquitted mainly because it emerged that Francis Heaulme - a notorious serial killer now serving a life sentence for nine murders - was in the area at the time of the murder.

But the trial of Heaulme, dubbed the "Criminal Backpacker" by the media, was suspended after dramatic last-minute testimony implicating Leclaire.

A witness said Leclaire had told her in 2012 that he had attacked the boys, although he denied killing them.

In response, Leclaire, who was appearing as a witness in the trial, said he had "made up" the story.

Leclaire's lawyer described his client as "a slightly frustrated old man who has lived alone since his father died" with few friends but very attached to his dog.

Leclaire himself told a newspaper in March that he just wanted to be "left alone" by the case which had "ruined" his life.